【作者】 曹荣光；

【导师】 由世俊；

【作者基本信息】 天津大学 ， 供热、供燃气、通风及空调工程， 2011， 博士

【摘要】 本文系统地研究了区域供冷变流量输配系统的能耗评价方法,并在其基础上分析了区域供冷多级泵系统的能效。针对具体的工程问题,研究了变流量输配系统中如何保持调速水泵高效运行的具体技术措施。主要内容分为六章,研究要点如下:第二章研究了区域供冷输配系统能耗的评价方法。在输配系统能耗分类的基础上,定义了评价输配管网能耗特性的指标-输配效率。对于拓扑结构和管径参数已经确定的输配管网,该指标对输配能耗的评价具有客观性,对降低输配能耗有具体的指导意义,可以为输配系统形式和运行方式优化提供独立判据。该指标可以量化输配系统的最大节能量,为控制系统设计提供目标。对区域供冷变流量输配系统中调速水泵的效率进行了研究,提出了在系统设计和运行过程中如何实时追踪调速水泵高效区的技术措施。第三章研究了输配系统动力学数学模型的建立方法。建立了输配系统设计工况和运行工况管网动力学数学模型。通过运行工况管网模型的求解,可以计算运行工况下管网各用户的阻抗值以及系统循环动力设备的运行状态,为第二章定义的输配能耗和输配效率提供理论计算方法。第四章研究了区域供冷输配管网阻抗值辨识方法。提出了基于现场辨识和系统辨识相结合的管网阻抗混合辨识法,建立了数学模型,并研究了数学模型的数值计算方法。对示例工程的数值实验表明,该辨识方法得到的管网阻抗值,在用于输配系统运行工况分析时具有满意的精度。通过本章的研究,为第三章所建立的管网模型在实际工程中的应用清除了障碍。第五章研究总结了区域供冷输配系统通用性设计方法,以量化各不同输配方案的使用功能,为各不同输配方案的比较提供统一的前提。第六章利用第三章所建立的管网动力学模型,对多级泵系统的工况模拟方法进行了研究,提出了旁通管用户多级泵系统工况模拟的简化方法。第七章是工程实例研究。综合运用本文提出的输配效率分析方法,结合工程实例,研究了多级泵系统能效评价方法,分析了多级泵系统的应用意义。本文的研究成果,可以直接为区域供冷多级泵系统形式和控制方式选择提供充分的理论和计算依据,可以节约大量的科研投入资金。本文的研究可以为包括区域供热输配系统在内的其他暖通空调输配系统的节能研究提供参考。更多还原

【Abstract】 The evaluation method of the energy consumption of the variable flow transmission and distribution system is systematically studied in this dissertation, based on which the energy efficiency of the district cooling multistage pump system is analyzed. In connection with the engineering problem, technical measures for tracking the high efficiency zone of variable speed pumps in variable flow transmission and distribution systems are brought forward. The main content of this dissertation is divided into six chapters, and is as follows:The second chapter is to study the evaluation method of energy consumption of the transmission and distribution system of the district cooling system. Based on the classification of the energy consumption of the transmission and distribution system, the transmission and distribution efficiency is defined, which is to evaluate the energy consumption performance of the transmission and distribution pipe network. For the pipe network whose topology and parameters have been identified, the transmission and distribution efficiency can objectively evaluate its energy consumption, which can provide specific guidance for reducing energy consumption. The transmission and distribution efficiency can provide an independent criterion for the optimization of the system form and operation method of the transmission and distribution system. The transmission and distribution efficiency can quantify the maximum energy saving value, which provides an objective for the control system design. The efficiency of the variable speed pump in the variable flow transmission and distribution system is studied and technical measures for tracking the high efficiency zone of variable speed pumps are brought forward.In chapter three, the dynamic mathematical model of the transmission and distribution system is studied. The dynamic mathematical model is classified into the design condition and the operation condition. By solving the operation condition dynamic mathematical model, the impedance of all users and the operating condition of all pumps can be calculated, which can provide theoretical calculation methods for the energy consumption of transmission and distribution system and the transmission and distribution efficiency which are defined in chapter two.Chapter four focuses attention on the pipe network impedance identification method of the district cooling transmission and distribution system. Based on the combination of the site identification and the system identification, the complex identification method is brought forward. The mathematical model of the complex identification method is established and the numerical calculation method is studied. Numerical experiments on the sample project shows that the pipe network impedance which is obtained by the complex identification method has the satisfactory accuracy when it is used for operation condition analysis of the transmission and distribution system. The study of this chapter can clear the obstacle for the practical application of the dynamic mathematical model which is established in chapter three.Generic design methods of the variable flow district cooling transmission and distribution system are studied and summarized in chapter five, which is to quantify the functions of different transmission and distribution programs and provide a unified premise for different programs comparison.In chapter six, simulation methods of operation conditions of the district cooling multistage pump system are studied by using the dynamic mathematical model of the pipe network which is established in chapter three. The simplified method of the operation condition simulation of the bypass user multistage pump system is proposed.Chapter seven is about case study. With an engineering example the energy efficiency evaluation method of the district cooling multistage pump system is investigated by using the transmission and distribution efficiency evaluation method which is proposed in this dissertation. The significance of the application of the multistage pump is analyzed.The results of this dissertation can provide sufficient theoretical and computational basis for the selection of the system form and control method of the district cooling multistage pump system, which can save a lot of scientific research funds. The research of this dissertation can provide references to the energy saving researches of all the other HVAC transmission and distribution systems.更多还原